| Water bamboo is a kind of deep people favorite aquatic vegetables,taste crisp and tender,nutritious value.However,fresh water bamboo is concentrated and not easy to store,Water bamboo commonly harvested at room temperature for about 5 days will occur weightlessness,yellowing,lignification and other quality deterioration phenomenon and then lose the value of commodity and edible value.Therefore,it is the main direction of studying the storage of bamboo shoot after the study of the preservation of fresh water bamboo storage and the quality of the storage period.Taking fresh water bamboo as material,through the use of different concentration of NO treatment after mining water bamboo to explore the best concentration using the NO preservation of postharvest water bamboo,after choosing the NO and MA postharvest storage processing water bamboo,explore their effects on refrigerated water bamboo quality and physiological metabolism.The main findings are as follows:(1)The best NO treatment of post harvest water bamboo stem concentration screening:In this study,we used different concentrations of NO to treat the post-harvest frozen water bamboo,and the best NO treatment concentration of dried water bamboo was studied by studying the difference of quality of frozen water bamboo after different concentrations of NO.The results showed that low concentration of NO could play a certain role in maintaining quality during the postharvest period of water bamboo,while high concentration of NO could accelerate the deterioration of the quality of wild rice stem.The results of comprehensive test showed that 30μL/L NO treatment could improve the sensory quality and nutritive quality of dried water bamboo.It could be used as the best concentration of water bamboo.(2)Effects of NO and MA on Active Oxygen Metabolism of water bamboo:There was significant(P<0.05)difference in the changes of quality and active oxygen metabolism between the NO group and the MA group with the control group of water bamboo.The NO treatment significantly(P<0.05)reduced the superoxide production rate and the H2O2 content compared with the control group,and inhibited the increase of MDA and electrical conductivity.MA group reduced the superoxide production rate and H2O2 content.inhibited the increase of MDA and electrical conductivity in the early stage of storage,but there was no significant(P>0.05)difference in the later stage of storage.Simultaneously,both of the MA group and the NO group significantly(P<0.05)inhibited the decrease of the activity of SOD,CAT,POD and GR.But oth of them had no inhibitory activity on APX and DHAR at the early stage of storage,and the activities of APX and DHAR were higher in the later stage.The activity of SOD and POD in the NO group was significantly(P<0.05)higher than that in the MA group,and the activity of CAT and APX in the NO group was significantly lower than that in the MA group in the early stage of storage,but higher in the later stage of storage.The DHAR activity is higher han that in the MA group in the early stage of storage,but lower in the later stage of storage,and there was no significant difference(P>0.05)between GR and GR group.The content of Vc and GSH in the group treated by NO and MA was lower than that in the control group,and the contents of Vc and GSH in NO group and MA group have no significant difference(P>0.05).The inhibitory effect of the three treatment groups on the metabolism of reactive oxygen species in postharvest water bamboo was as follows:NO and MA group>NO group>MA group(3)Effects of NO and MA on metabolism of frozen water bamboo cell wall:NO,MA and the combination group were inhibited by the reduction of the hardness of water bamboo,28 days after storage were 58.4%,60.3%and 66.3%,respectively,while the control group was only 51.2%,Environmental scanning electron microscopy also found that NO,MA and the combined group were able to maintain the structural integrity of the leukocyte wall.NO,MA and the combination group were decreased by 47.7%,52.7%and 45.8%respectively,while the control group decreased by 69.2%.The original pectin increased by 57.6%,41.4%.33.1%%and 82.5%,respectively.The content of cellulose and lignin increased by 124%,104%,82%and 113%,152%and 84%respectively,while the control group increased by 182%and 244%respectively.The results showed that the three treatments could maintain the stability of water bamboo cell wall constituent compared with the control group,and the combination group had significant effect.The activity of CEL was significantly(P<0.05)higher than that of the control group,and the activity of PME,PG and PAL was significantly(P<0.05)lower than that of the control group,and the relative(4)Effects of NO and MA on Respiratory Metabolism of water bamboo:NO and combined group significantly inhibited the respiration rate of postharvest water bamboo stem.While the MA did not show a significant inhibitory effect.NO and MA could inhibit the decrease of ATP content in wild rice stem,and NO Group.MA group and combination group were 32.9%.46.4%and 66.3%higher than the control group.Compared with the control group.NO group,MA group and combination group improved the activity of key enzyme MDH,SDH and CCO in the tricarboxylic acid cycle,maintaining the normal function of mitochondria,The difference between NO group and MA group uas not significant,but the combination group had the best effect.At the same time.NO and MA inhibited the H-ATP enzyme,Na-K ATP enzyme.Ca2+-ATP enzyme activity decreased after 28 days storage,control group,NO group,MA group and Ca2+ group with the content of mitochondria were 5.9 g.g-1Pr-1,5.3 g.g-1Pr-1,5.5 g.g-1 Pr-1 and 4.9 g.g-1Pr-1,indicating that NO and MA treatment could maintain water bamboo cells steady state.(5)In summary:NO,MA and combined treatment of post-harvest frozen water bamboo,to maintain good quality and metabolic stability of water bamboo.The results showed that the combination of the three treatments was as follows:combined group>NO group>MA group... |
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